Picasso’s masterpieces made of house paint

By The New York TimesPublished February 23, 2013 - 12:00am Last Updated February 23, 2013 - 8:37am

Scientists using a high-energy X-ray instrument say they have solved the long-running debate over what kind of paint Picasso used in his masterpieces. (CHRIS GASH/The New York Times)

Scientists using a high-energy X-ray instrument say they have solved the long-running debate over what kind of paint Picasso used in his masterpieces.

It was common house paint, said Volker Rose, a physicist at the Argonne National Laboratory who led the study, published in Applied Physics A: Materials Science & Processing.

“We were looking into pigments taken from Picasso’s white paint, which from a material perspective is zinc oxide, and we were able to study the impurities that are there,” Rose said.

The scientists also bought samples of decades-old house paint on eBay. After comparing those samples with Picasso’s paint, they determined that the two shared the same chemical makeup.

The instrument was a hard X-ray nanoprobe, developed by the Department of Energy to give scientists a close-up view of the chemical elements in physical materials.

In his regular work, Rose uses the nanoprobe to study zinc oxide, a key ingredient in batteries, energy-saving windows and liquid-crystal displays for computers and television. Because zinc oxide exists in white paint as well, it made a valuable clue for the physicist to learn about Picasso’s paint.

Some art historians have long held that Picasso was among the first major artists to switch from traditional artists’ paint to house paint, which is more affordable and creates a glossy image without brush strokes.

A MOLE’S NOSE KNOWS, WITH STEREO SNIFFING

Humans and many other mammals see and hear in stereo. But what about smell?

“People have wondered for a long time whether smell has this component as well,” said Kenneth C. Catania, a biologist at Vanderbilt University. Now he and colleagues report in the journal Nature Communications that common moles, which are blind, have the ability and use it to swiftly locate prey.

Catania created a chamber with food wells spaced around a semicircle and watched as moles detected the food. The chamber was sealed, so changes in air pressure would indicate that the animals were sniffing. Moving their noses back and forth, the moles zeroed in on the food in less than five seconds.

Catania then blocked one of the moles’ nostrils with a plastic tube. When the left nostril was blocked, the moles veered off to the right, and when the right was blocked, they veered to left. Although they were still able to find the food, it took them much longer.

To confirm that the moles use stereo sniffing, Catania put plastic tubes in both nostrils and then crossed them.

This confused the moles, causing them to think that food to their right was actually located to their left. But their response confirmed that the moles in fact use stereo sniffing, Catania said.